What is the recommended management for a patient with less than 50% coronary, carotid, or peripheral arterial stenosis?

Management of Less Than 50% Arterial Stenosis

For stenosis less than 50% in any arterial territory (carotid, coronary, renal, or peripheral), revascularization is not indicated and intensive medical therapy is the standard of care.

Carotid Artery Stenosis <50%

Revascularization is explicitly contraindicated for carotid stenosis <50%, regardless of symptom status 1. The 2017 ESC Guidelines provide a Class III, Level A recommendation against revascularization in patients with <50% carotid stenosis 1.

Medical Management for Carotid Disease <50%

• Antiplatelet therapy: Single antiplatelet therapy (SAPT) with aspirin 75-325 mg daily or clopidogrel 75 mg daily is recommended for symptomatic patients 1
• Statin therapy: High-intensity statins are mandatory for all patients with carotid stenosis, targeting LDL-C <1.8 mmol/L (70 mg/dL) or a ≥50% reduction from baseline 1
• Blood pressure control: Target <140/90 mmHg 1
• Risk factor modification: Smoking cessation is essential 1

Important caveat: For asymptomatic patients with isolated carotid stenosis <50%, antiplatelet therapy is not routinely indicated due to lack of proven benefit 1.

Vertebral Artery Stenosis <50%

Revascularization of asymptomatic vertebral artery stenosis is not indicated, irrespective of the degree of severity 1. Even for symptomatic vertebral artery stenosis, endovascular treatment is only considered (Class IIb, Level C) for lesions ≥50% with recurrent ischemic events despite optimal medical management 1.

Medical Management for Vertebral Artery Disease

• Antiplatelet therapy: Aspirin (or clopidogrel if aspirin not tolerated) should be administered in all patients, irrespective of symptoms 1
• Statin therapy: Statins are recommended for all patients with vertebral artery disease 1

Renal Artery Stenosis <50%

Routine revascularization is not recommended for renal artery stenosis secondary to atherosclerosis 1. This is a Class III, Level A recommendation from the 2017 ESC Guidelines. Even for stenosis ≥50-70%, the ACC/AHA guidelines note that the usefulness of percutaneous revascularization of asymptomatic unilateral hemodynamically significant stenosis is not well established 1.

Medical Management for Renal Artery Disease

• Antihypertensive therapy: ACE inhibitors or ARBs are recommended for treatment of hypertension associated with unilateral renal artery stenosis 1
• Alternative agents: Calcium channel blockers, beta-blockers, and diuretics are also recommended 1
• Statin therapy: As part of comprehensive cardiovascular risk reduction 1

Lower Extremity Arterial Disease (LEAD) <50%

For peripheral arterial stenosis <50%, the ACC/AHA guidelines indicate that endovascular treatment of a stenosis lacking a hemodynamically significant pressure gradient is not indicated 1. Stenoses of 50-75% diameter may not be hemodynamically significant and require pressure measurements to determine significance 1.

Medical Management for LEAD

• Antiplatelet therapy: SAPT is recommended in symptomatic patients 1
• Statin therapy: Statins are recommended in all patients with LEAD, targeting LDL-C <1.8 mmol/L (70 mg/dL) 1
• Blood pressure control: Target <140/90 mmHg 1
• Smoking cessation and exercise: Mandatory for all patients 1

Critical distinction: Antiplatelet therapy is not routinely indicated in patients with isolated asymptomatic LEAD due to lack of proven benefit 1.

Surveillance Strategy

For patients with <50% stenosis in any territory:

• Annual follow-up with duplex ultrasound is appropriate for carotid stenosis <50% 2
• Cardiovascular risk factor assessment should be performed at each visit 1
• Progression to ≥50% stenosis warrants more frequent surveillance (every 6 months) and consideration for intervention if symptomatic 2

Common Pitfalls to Avoid

• Do not perform prophylactic revascularization for asymptomatic stenosis <50% in any arterial territory—this strategy has no proven benefit and exposes patients to procedural risk 1
• Do not withhold statin therapy—intensive lipid-lowering is the cornerstone of medical management regardless of stenosis severity 1, 3
• Do not assume all stenosis <50% is benign—these patients still require aggressive cardiovascular risk factor modification as they have established atherosclerotic disease 1
• Do not prescribe antiplatelet therapy reflexively for asymptomatic disease—the evidence does not support routine use in asymptomatic LEAD or isolated asymptomatic carotid stenosis 1